This invention relates to an apparatus for cutting dry edible beans and other agricultural products in the field, and particularly to a device for attachment to a farm tractor. The invention is an improvement over prior art bean cutters such as that described in U.S. Pat. No. 3,857,225, issued Dec. 31, 1974, which discloses a bean cutting device mounted forward of a tractor front wheel on a frame which is supported by additional and auxiliary forward wheels, and for which the various adjusting features relating to the height of the cutting blade and cutting blade angle are accomplished by adjustments made to the entire frame assembly upon which the cutting blades are attached.
In the cutting and thinning of bean plants which are typically planted in parallel rows across a field, it is desirable to work a number of rows at a time with spaced cutting blades. The cutting blades are preferably mounted on a frame assembly which is then carefully steered through the field with the cutting blade set to an optimum subsurface depth which is constantly maintained as the apparatus is propelled across the field. It is desirable that each of the cutting blades follow the general contour of the land as the device moves, and it is further desirable that the apparatus be responsive to small corrections in steering the drive tractor to ensure that proper clearance is maintained between the rows of beans, and that all plants are completely cut by the apparatus.
A particular type of cutting blade has been used for this purpose, having a lower edge for accomplishing the cutting and having a cylindrical drum positioned above the edge for preventing beans from becoming tangled in the cutter, and having an upper edge for deflecting bean plants away from contact with the frame and other portions of the drive mechanism. The cutting blades are powered with a rotating hydraulic drive source to cause them to rotate at a relative constant speed independent of the speed of the tractor.